In the United States, stream restoration is currently a billion-dollar industry. Though it is commonly used as a method for stream impact mitigation, Total Maximum Daily Load (TMDL) crediting, and stormwater management, there is little scientific knowledge defending stream restoration as an effective tool for addressing these issues. In particular, few studies have been conducted with the goal of providing recommendations for future design improvements.
To improve stream restoration success rates by advising practitioners and stakeholders in site selection and project assessment, a selection of completed Maryland stream restoration projects were assessed at the watershed and project level. Watershed, site, and design characteristics were quantified using ArcGIS, restoration design plans and monitoring reports. Using current literature and expert advice, stream restoration assessment methodologies were developed to assess geomorphic function and design success both in the field and through monitoring reports. Multiple linear regression analysis and related methods were then used to identify correlations and relationships between watershed- and project-level characteristics and stream restoration success. At the watershed scale, land use was most strongly related to functional success, with projects in more natural watersheds exhibiting higher geomorphic function. Design scores correlated negatively with watershed area. At the project level, projects with higher width to depth ratios scored higher on the functional assessment, while particle size was negatively correlated with geomorphic function. Study results suggest stream restoration designs are improving over time, but the ability to determine project success from monitoring remains limited. / Master of Science / In the United States, stream restoration is currently a multi-billion-dollar industry. Though it is commonly used as a method for water quality improvement, stormwater management, and habitat restoration after human disturbance, there is little scientific knowledge defending stream restoration as an effective tool for addressing these issues. In particular, few studies have been conducted with the goal of providing recommendations for future design improvements.
To improve stream restoration success rates by advising practitioners and stakeholders in site selection and project assessment, a selection of completed Maryland stream restoration projects were assessed at the watershed and project level. Watershed, site, and design characteristics were quantified using spatial data analysis software along with restoration design plans and monitoring reports. Using current literature and expert advice, stream restoration assessment methodologies were developed to assess stream ability to transport water and sediment, as well as design resilience using monitoring reports, and during field visits. Data analysis showed projects built in more rural, natural watersheds were more similar to undisturbed streams. Projects constructed in large watersheds were less likely to remain stable after repeated storm events. At the project level, projects that were wider rather than deep were more functional, while those with significant amounts of large rock were less successful. Stream restoration designs seem to be improving with time, but the ability to determine project success from monitoring remains limited.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/95491 |
| Date | 11 November 2019 |
| Creators | Withers, Urban Samuel |
| Contributors | Biological Systems Engineering, Thompson, Theresa M., Hession, W. Cully, Smith, Eric P. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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